1. Field of the Invention
This invention relates generally to smoking articles and combustion means therefore. More particularly, the present invention relates to a constituent lighter which is integrally combined with a smoking article employing combustion of a pre-mixed gaseous fuel.
2. Description of the Related Art
Cigarette lighters that produce pre-mixed flames are well known in the art. For example, U.S. Pat. No. 3,915,623 teaches a burner for a cigarette lighter in which gaseous fuel is mixed with air prior to ignition in order to generate a stable flame. Also, U.S. Pat. No. 4,929,174 teaches a lighter in which gaseous fuel is mixed with air drawn into the lighter through an air vent, after which the fuel/air mixture is combusted in a combustion chamber. A pre-mixed flame is the product of a combustion process wherein the fuel is mixed with air in near stoichiometric proportions upstream of the ignitor and proceeds to nearly complete reaction upon ignition. Due to the near complete combustion reaction, the process produces almost no soot, uncombusted fuel nor products of incomplete combustion. Also, since the fuel is pre-mixed with air, the flame is not dependent upon the orientation of the lighter and it is able to burn within an enclosed space. Cigarette lighters that generate pre-mixed flames generally use venturies to entrain air, which is then mixed in nearly a stoichiometric ratio with a gaseous fuel to produce a mixture that, when combusted, generates the pre-mixed flame.
However, cigarette lighters are generally provided separately from the article that is to be smoked. As a result, the article to be smoked must generally be ignited in order to supply sufficient heat to the material with the smoking article that generates the smokable aerosol inhaled by the user. The ability to smoke an article without igniting the material to be smoked may provide certain advantages over previously known smoking articles. More particularly, a smoking article that does not have ignited tobacco or other smokable material may be less likely to generate inadvertent fires.
Inhalable aerosol generating devices that heat the aerosol generating material are also known in the art. WO 97/48294 discloses a device that heats a flavor-generating material using a combustible fuel. The heating device generates an unmixed diffusion flame and a heat exchanger to heat indirectly the air that contacts the flavor generating material. The heating device requires ducts through which off-gas from the combustion process may be vented. Such off-gas includes unreacted fuel and products from incomplete combustion. Such an indirect heating device expends more energy and requires a greater fuel storage capacity than a device in which the flavor-generating material is directly heated
It is therefore desirable to provide a smoking article having a lighter integral thereto by which a smokable material contained within the smoking article is directly heated without being ignited.
It is an object of the present invention to provide a lighter integral with a smoking article.
It is another object of the present invention to provide a lighter integral with a smoking article providing a pre-mixed flame.
It is a further object of the present invention to provide an attachment for a lighter to convert a conventional lighter to a lighter integral with a smoking article.
It is still a further object of the present invention to provide an integral lighter for a smoking article in which a flavor-generating material is directly heated without ignition thereof.
More particularly, the present invention is directed to a constituent lighter integral with a smoking article. The constituent lighter includes a tube and a gas burner which produces a stable, pre-mixed flame that may be contained within an enclosed space, such as a tube or flame chamber. The tube is sized to receive a rod containing a smokable material such as tobacco. The tube has an open distal end into which the rod may be inserted. A heat-conducting barrier is also included in the constituent lighter, so as to prevent the end of the rod from entering the flame chamber. The tube is in flow communication with the gas burner. The gas burner may include a flame chamber, a flame holder, a mixing chamber, at least one air inlet, and a nozzle. The nozzle is in flow communication with a fuel storage container in which is housed a gaseous fuel. The gas burner may also include an optional catalyst bed that may be activated by ignition of fuel within the burner.
In use, fuel is fed from the fuel storage container to the nozzle. The nozzle constricts the flow path of the fuel, thereby increasing the flow velocity. Once the gaseous fuel leaves the nozzle, the static pressure of the flow drops, thereby drawing air into the burner through the air inlet(s). The fuel and air travel to the mixing chamber where they become thoroughly mixed. The mixing chamber is in flow communication with the flame holder. The fuel/air mixture flows out of the mixing chamber, past the flame holder to the ignitor, which ignites the fuel/air mixture upon activation. The combustion of the fuel/air mixture produces a stable, pre-mixed flame that is contained within the flame chamber and is prevented from flashing back through the burner by the flame holder. With the proper fuel-to-air ratio, the combustion process produces virtually no soot, uncombusted fuel nor products from incomplete combustion. A rod containing a smokable material, such as tobacco, is inserted in the tube of the constituent lighter. The heat-conducting barrier allows heat transfer from the gas burner to the interior of the tube, while preventing the smokable rod from entering the flame chamber. The flame generated and contained in the flame chamber heats the rod for smoking. Alternatively, if the constituent lighter includes a catalyst bed, then the bed may be activated so as to heat the rod to a sufficient temperature to allow the rod to be smoked. In this case, the heat-conducting barrier separates the smokable rod from the catalyst bed, while allowing heat transfer therebetween. At least one opening contained within the side wall of the tube allows air to be drawn into the tube to the smokable rod by puffing. Alternatively, a gap may be formed between the tube and the burner, through which air may be drawn into the tube. In this manner, a smokable material may be smoked within an article having a constituent lighter.
The lighter of the present invention may be included in smoking articles having various configurations. The smoking article may have a cigarette or cigar-shaped configuration; or, it may be shaped like a pipe. Another embodiment of the smoking article may be shaped like a conventional lighter with a tube extending therefrom. The smokable material may include any known aerosol-generating material well known in the art, such as tobacco. The smokable material may be packaged in a rod, such as a cigarette, or it may alternatively be loose material.
It will become apparent that other objects and advantages of the present invention will be obvious to those skilled in the art upon reading the detailed description of the preferred embodiment set forth hereinafter.